The mechanisms of binding and entry of alphaherpesviruses are unclear. These early events in the herpesvirus life cycle are important to our understanding and our attempts to control herpesvirus diseases. We are investigating the binding of varicella zoster virus (VZV) glycoproteins and glycoprotein B from herpes simplex virus type 2 (HSV-2) to cell membrane preparations from a variety of cultured cell-lines, to isolated proteins, glycoconjugates, and to synthetic peptides. The genes for the major-envelope glycoproteins of VZV have been cloned into high level expression vectors including the baculovirus expression system. Inhibition of VZV infectivity in diploid human lung cells is being used assess potential receptor-mimicking molecules for ability to block VZV binding and infection of cells. Monoclonal and polyclonal antibodies to cell membrane proteins are being developed to identify the specific cell surface molecules that serve as receptors for VZV. We found that heparin inhibited infectivity of VZV, in contrast, other glycosaminoglycans did not inhibit VZV infectivity. VZV binding to cell membrane preparations was inhibited by added heparin suggesting that an important mechanism of interaction of VZV with cells involves heparin. Soluble VZV glycoprotein B has been produced using the vaccinia-T7 expression system to investigate glycoprotein to heparin receptor binding using ELISA based and biosensor technologies. The interaction of glycoprotein B of herpes simplex virus type 2 (HSV-2) with heparin-like glycosaminoglycans is being investigated using the biosensor technique. This study will lead to a detailed understanding of the affinity and specificity of the HSV gB to heparin interaction and serves as a model system to explore inhibitor compounds that may be used to interrupt the interaction of herpesviruses with their cellular receptors and therefore act as antiviral drugs.